The increasing digitalization in the process and the end-result of public service, a phenomenon widely known as e-government, is changing the range and ways of collaboration among governments and their stakeholders. Especially with the pervasive use of social media for knowledge sharing, today’s local governments are teaming up with their non-government stakeholders in an unprecedented width and depth to exchange knowledge and resources to build digital public services together. While these collaborative initiatives benefit from the complementation of knowledge and resources that are associated with extensive participation, these initiatives also exist under a shadow of confusion and conflict when organizing the changing range and relationships of stakeholders, aligning technology uses with divergent objectives of knowledge sharing, as well as coordinating different distributions of decision-making power and accountability. To tackle these issues, in this dissertation I develop an understanding of the co-evolution of governance, organizational form of e-government collaboration through the mediation of social media. Here I define governance as the attempts to address the issue of coordination, and organizational form as the structural features of the e-government collaboration. And I define social media as the Internet-based collaborative technologies that are accessible to both government and non-government stakeholders for creating, circulating, sharing and exchanging knowledge. My primary research inquiry is thus how do the governance and organizational form of e-government collaboration occur through the mediation of social media? To pursue this line of inquiry, I further explore the relationship between social media and the governance and organizational form of e-government collaboration. Specifically, I ask: • How does the governance of e-government collaboration occur through the mediation of social media? • How does the organizational form of e-government collaboration occur through the mediation of social media? Conceptually I take an ensemble view to understand the relationship between social media and organizational changes (i.e., governance and organizational form) and argue that while social media has the potential to change social arrangements, these arrangements also influence the use of social media. In particular, I use the technology enactment framework as a conceptual map to identify the embeddedness of technology adoption in institutional, organizational and cognitive arrangements. Furthermore, I complement the framework with the theory of institutional logics, technology frames of references, and temporary organization, to operationalize the understanding of the institutional, organizational as well as cognitive arrangements. I choose e-government in China as the empirical setting to address the research questions for its unique environment, including its recent strong policy push for e-government initiatives and public-private collaboration, its complex public administration environment, as well as the pervasiveness of social media (i.e., WeChat) for work communication in both public and private spheres. Such an environment provides a good number of e-government collaboration cases that are characterized by the heterogeneity of stakeholders, mediation of social media, innovative administration arrangements, and that can be followed and studied from their early stages. The dataset for this dissertation is collected from four cases of e-government collaboration in China. To better understand the development of e-government collaboration through the mediation of social media over time, I conducted a longitudinal study on one of the cases, of which the communication between the stakeholders is primarily mediated through the Chinese social media WeChat. For data collection, I used qualitative methods including interviews, participant observations, as well as document analysis. For the first research question, the findings indicate the key dimensions in the governance of e-government collaboration center around the distribution of decision-making power and accountability between government and non-government stakeholders. And social media, as a knowledge-sharing platform, is crucial for achieving balances as such in an undefined collaboration, as it provides ambiguity between stakeholders’ interests and needs, while still allowing stakeholders to develop a sense of consensus and informedness. For the second research question, the findings indicate that e-government collaboration can be organized differently through the mediation of social media. Nevertheless, a long-term examination shows the organizational form of e-government collaboration has to accord with the institutional logics at play. The form changes as the dynamics of institutional logics change. During the transition of these organizational settlements, social media plays an important role as a sandbox for experimenting with configurations of organizational structures, as well as a repository for shared knowledge and experiences. This dissertation makes three central contributions: First, it contributes to the conceptualization of governance in the era of e-government by highlighting the role of social media and its enactment in the occurrence of governance, and proposing an empirically driven typology of adaptive governance. Second, it contributes to the understanding of the organizational form of e-government collaboration by identifying the social media mediated hybridization process, and the characteristics of a social media enabled organizational form. Third, the findings extend the understanding of social media adoption in the context of e-government collaboration by providing a longitudinal account of social media enactment, and insights in the relationship between social media and government transformation.